The Ring Main Units solution

Lisäarvot

Mains drivers:

In the large market of containers and booming MV applications, to provide efficient ships and gain in construction expenses shipbuilding companies are looking for innovative solutions

Solution in brief

The Ring Main Unit solution combines all MV functional units to enable connection, supply and protection of one or two transformers on an open ring network.

Value proposition

Opex reduction: length of HV cables reduced, shortening average ratio >30% for the configuration
Peace of mind: The new RM6 generation benefits from the accumulated experience acquired from the 850,000 functional units that equip electrical networks in more than 50 countries in America, Asia, Europe and Australia.
Improvment of network maintainability and availability :

A failed cable section on the HV loop can be disconnected

An automatic reconfiguration of the HV loop after a fault detection can be achieved.

Differentiation factors:

Why is the HV loop adapted to a ship ?

A HV loop network is composed of several substations, called RMU (Ring Main Units). Each substation consists of several HV functions.

Two HV switch-disconnectors ensure the closing or opening of the HV loop.

The protection of one or two transformers can be done through a circuit-breaker or a fuse switch combination.

The electrical architecture of a ship is divided in two parts:

the machinery space composed of propulsion motors, thrusters, power generation, pumps... Generally, the associated electrical architecture is a radial configuration.
the cargo, like for example the accommodation part of a cruise liner. Several HV/LV transformers are dispatched in the different ship's zones.

Therefore, a HV loop configuration is an adapted solution as the loads can be supplied as near as possible.